The dwarf water cobra (Naja nana) is a small, venomous species of aquatic cobra found in the Democratic Republic of Congo (Katanga). It was first described by Marcel Collet and Jean-Francois Trape in 2020, based on two specimens from Lake Mai-Ndombe.
Naja nana is classified under the genus Naja of the family Elapidae, and considered a member of the Boulengerina subgenus, along with related species such as Naja annulata, Naja christyi, and Naja melanoleuca. The genus name Naja is a Latinisation of the Sanskrit word (Sanskrit: [[:wikt:नाग#Sanskrit|नाग]]), meaning "cobra”; the species name nana derives from the Latin word, nanus, which means feminine, in reference to its small size.
The dwarf water cobra typically doesn't grow longer than,[1] unlike the two other semiaquatic African Naja species, Naja annulata and Naja christyi, both of which can attain lengths of up to about .[2]
Distinguishing features of the species include its characteristic defensive posture, its aquatic lifestyle, the straight-row arrangement of its dorsal scales, and its distinctive coloration: black with small white or yellowish spots, a whitish abdomen, and a black underside of the tail.
The eggs of the dwarf water cobra are large and elongated, and require 70 days of incubation to hatch.[3]
Dwarf water cobras can swim and climb, but generally prefer a terrestrial habitat, although they will hunt and defecate in water when able.[4] In the wild they are exclusively piscivorous,[5] [2] although in captivity they are often fed a rodent-based diet.[4] One case of cannibalism of a conspecific snake is known.[2]